Central air-conditioning systems are adopted generally in buildings of medium size or larger. In central air-conditioning systems, cold water or hot water is prepared at one location, and the prepared cold water or hot water is circulated to each room in a building.
However, individual distribution package air-conditioning systems, that is, multi-air-conditioning systems for buildings are increasingly adopted these days, in view of the fact that they are inexpensive, easily installed, and easily used by occupants. In multi-air-conditioning systems for buildings, indoor units are provided in respective air-conditioning zones that are allocated as air-conditioned spaces, and the plurality of the indoor units are connected to one outdoor unit. In this way, the multi-air-conditioning systems for buildings provide individual distribution package air-conditioning systems. For example, as a multi-air-conditioning system for buildings, Patent Literature 1 discloses a technique of providing an exact required capacity depending on a calculated heat load.
Air-conditioning system control devices that control air-conditioning systems are generally desired to increase the operation efficiencies of air-conditioning apparatus for the purpose of energy-saving operation. For example, as a central air-conditioning system that increases the operation efficiencies of air-conditioning apparatus, Patent Literature 2 discloses, on the assumption that a plurality of heat source apparatus are present, a technique of creating optimum operation patterns of the plurality of heat source apparatus depending on a heat load by preparing performance characteristics of the respective heat source apparatus. In addition, for example, as an air-conditioning system that increases the operation efficiencies of air-conditioning apparatus, Patent Literature 3 discloses a technique of stopping an air-conditioning apparatus in the case where a heat load that decreases the operation efficiency of the air-conditioning apparatus is present.